Vibration in a vehicle drive train has been a long-standing problem, and a torsional vibration damper assembly is desirable to neutralize any torsional vibrations emanating from the vehicle engine which could result in undesirable impact loads, vibration, noise, etc.
Torsional vibration damper assemblies have usually comprised straight resilient means, such as coil springs, which were forcibly bowed through the use of clips, wedges, spring separators or dividers, or the like to obtain the desired arcuate shape. In addition, a plurality of shorter straight springs were sometimes substituted for the longer bowed springs along the path that would have been occupied by the longer bowed springs. Such configurations, however, were complicated, requiring a plurality of precise parts to complete the assembly. Thus, such assemblies were difficult to manufacture, maintain and operate, which translates into a higher product cost.
To address this past problem, an arcuate spring was developed as disclosed in U.S. Pat. No. 5,052,664, which is incorporated herein. The '664 patent discloses the use of an arc opening process to form the arcuate spring. The arc opening process is critical step of the standard arcuate spring manufacturing process; however, such arc opening process is very time consuming.
In view of the current state of the art for the formation of arcuate springs, there is a need for an improved process for forming arcuate springs, arcuate springs having improved performance, and a process for lowering the manufacturing cost of the arcuate spring.